The present invention relates to a magnetic core and, more particularly, to a high power pulse magnetic core such as saturable core impulse source for lasers as an induction core for a linear accelerator.
Generally, a high power pulse magnetic core, for example an induction core of a linear accelerator, operates essentially as a 1:1 transformer and accelerates the beam of charged particles in the center of the core by a voltage which appears across a gap.
Recently, there has been proposed a pulse source adapted for lasers of the type of a magnetic pulse compressor which operates with high power and high voltage. The pulse compressor serves to convert a pulse generated by the power source having a wide pulse width into a high power pulse having a relatively narrow pulse width. This conversion is achieved by utilizing a saturation phenomenon of the magnetic core incorporated in the pulse compressor.
In a conventional technology, the magnetic core for the high power pulse generation is made of a material having a high saturation magnetic flux density and a high rectangular ratio of a magnetization curve. For this purpose, a magnetic core is formed by alternately laminating or winding a thin metallic film made of an iron based amorphous alloy or cobalt based amorphous alloy and an electrically insulating film made of a polymeric film such as polyimide film.
The magnetic core formed by alternately laminating or winding the polymeric film such as the polyimide film as the insulating layer and the magnetic film is then thermally heated. However, the polymeric film is liably subjected to heat shrinkage by such heat treatment and, hence, the heat shrinkage adversely affects the magnetic film to apply compression stress, resulting in the lowering of the rectangular ratio of the magnetization curve and degrading the magnetic characteristic of the magnetic core.